RobOps – Approaching a Holistic and Unified...

RobOps – Approaching a Holistic and Unified Interface Service Definition for Future Robotic SpacecraftSteffen Jaekel, Bernhard Brunner (1)Christian Laroque, Zoran Pjevic (2)Felix Flentge (3)Thomas Krueger, and André Schiele (4)

(1) German Aerospace Center (DLR), Robotics and Mechatronics Center(2) OHB System AG(3) ESOC(4) ESTEC

www.DLR.de • Chart 1 RobOps – Approaching a Holistic and Unified Interface Service Definition for Future Robotic Spacecraft

Introduction – Space Robotics

www.DLR.de • Chart 2

- Future and already deployed robot applications in space:

- In-space robotic assembly (ISRA): SSRMS, SPDM

- EVA assistance: SSRMS, Robonaut, DLR‘s Justin, (small) satellitesfor inspection: SPHERES

- Robotic exploration: MER‘s

- On-orbit servicing (OOS) for prolonging lifetime of operational satellites, repair & refuel (RRM), extend or upgrade functionality (Hubble)

- OOS for active debris removal from LEO or re-orbiting into graveyard orbit in GEO

RobOps – Approaching a Holistic and Unified Interface Service Definition for Future Robotic Spacecraft

Justin

ROKVISS

e.Deorbit

Challenges of Robotic Spacecraft


Source: Airbus, DLR

Distributed Mission Architecture - METERON


Current Mission Operation Standards


- Current Mission Operations standards – e.g. Packet Utilization Standard (PUS) - are madefor the operation of classic spacecraft – mostly from one ground station - not for autonomousspace robots

- Partly new CCSDS approaches to standardization:- File delivery, Asynchronous Message Service (AMS), Disruption-tolerant Network

(DTN)- MO: Message Abstraction Layer (MAL), Monitor and Control Common Services (MO)

- RobOps approach:

- Effective control approach for autonomous robotic spacecraft, attached roboticdevices and arbitrary subsystem equipment holistic

- Clear distinction between interface service semantics and method of transport

Transport

Semantics

RobOps Study Contents


1. Communication

2. Control Modes

3. Roles & Responsibilities

4. Scenario Analysis

5. Service Definition

6. Technology Analysis & Implementation

7. Demonstration Prototype

Communication


- Dominant barrier: space- Properties of communication channel restricts capabilities- Higher delay, jitter, low data bandwidth increased autonomy- Communication window – relay satellites- Deep-space communication with DTN

Possible Control Modes


- Possible control modes depend on mission architecture and given communication delay as major barrier between operator and robot

- More system autonomy equals less human control and intervention

- Manual control, assisting, shared and supervized autonomy

- Monitoring: global, subsystem specific in real-time (telepresence), ad-hoc, post-hoc

Autonomous Control

Shared/Supervized Autonomy/Control

Manual Control

Syst

em A

uton

omy

• Algorithms pass real-time decisions based on a variety of sensor input and control the spacecraft and robotic manipulator

• No human control

• Autonomous algorithms execute human high-level control inputs, e.g. waypoints for path planningalgorithms

• High-level human control

• The human operator steers the system completely manual

• Low-level human control• Telepresence with haptic feedback

Interaction / Hum

an Control

Assisting Autonomy

• Autonomous algorithms support the operator in his manual system control, e.g. collision avoidance

• Mid-level human control

Roles and Responsibilities


- Classic roles and responsibilities were analyzed for classic satellite operations

- Partly confusing nomenclature differences between ESOC, GSOC and NASA

- Robotic operations:

Remote site

Orbiter

Mission control center

SOM SOE SPACON

report

command

Satellite

RO

RO

Robotic Spacecraft

Commander

Robotic satellite operations

Ground-controlled robot

Classic satellite operations

astronaut-controlled robot

- Very small time scale for reaction

- Direct control of robotic payload and decision-making by robotic operator (RO)

- Robotic Operations Manager (ROM) and Engineer (ROE) set goals and supervise operations

Scenario Analysis


OOS Free-FlyerRover

Scenarios

Service List

Use Cases

1.2.

3. Levels of Autonomy

Structuring Telerobotic Services


1. Functions

2. Mission Architecture

sensesense2. Sequencing Layer

3. Reactive Layer

Pre-condition

Post-conditionAction

sense

Action

Re-plan

Action finished

New action

New plan

Three Tier (3T ) layers Main service classes

Scheduling

EventEvent

Planning1. Deliberative Layer

Configuration Monitoring Control

Subsystem

System

Mission Mission

System 1

Subsystem 1 Subsystem n

System n…

…

System Level 3

System Level 2

System Level 1 System 1

System 2

System 5 System 6

System 4…


Del

iber

ativ

e La

yer

3T Layers of Autonomy

(1) Control

(A) Mission

Sequ

enci

ng L

ayer

Rea

ctiv

e La

yer

Classic SpacecraftOperations

AutonomousOperations

System Scheduling

Sybsystem Planning(e.g. path planning)System Planning

Mission Scheduling

Mission Planning

Subsystem Action(privatizable)

System Event

Mission Action

(2) Mon. (3) Config. (1) Control (2) Mon. (3) Config. (1) Control (2) Mon. (3) Config.

(B) System (C) Subsystem

1:n1:n

Architecture:

Function:Operator

Subsystem Scheduling(e.g. path sequencing)

System Action

Com

mon

Ser

vice

s

System Monitoring

Subsystem Monitoring

Mission Monitoring

MonitoringPath

Control & Config.Path

MissionEvent Subaystem Event

Planning

Scheduling Event

Action

Monitoring

Service Privatizations


- Functional approach to Monitoring & Control – focus on autonomy rather than specific subsystem or device (PCDU, AOCS, Robot Arm)

- Specific functionality is addresses via Privatizations

- Privatizations become Subservices, to be used across missions

Service, e.g. Action

Service Operation, e.g. executeAction

Operation specification1. Subservice, e.g. Robotic

2. Type: Motion

Parameters (defined by Subservice)e.g. cmd=SETPOSE, device=ARM, mode=CART,

syntax=XYZ_EULER, reference=ABS, poseData=(trans_x, trans_y, trans_z, rot_x, rot_y, rot_z)

Technology Analysis - Overview


- Message Abstraction Layer (MAL) and Mission Operations Services (MO)

- Communications:- Message Based Communications

- Data Distribution Service (DDS)- ActiveMQ- øMQ (ZeroMQ)- Asynchronous Message Service (AMS) over DTN

- File Based Communication- CCSDS File Delivery Protocol (CFDP)- File Transfer on Ground

- Decision fell on MAL over DTN for transport

DTN

MAL

RobOps

Implementation - Overview


High-Level Architecture of Robot Demonstrator


Demonstration at ESTEC


- Iterative implementation and testing approach

- Picture: local testing at ESTEC Teleroboticsand Haptics Laboratory with KUKA LWR-III setup and DTN over Intranet

- Privatizations…

Study Conclusions


- Holistic control approach for autonomous robotic spacecraft

- Action & Monitoring services were implemented and demonstrated with KUKA LWR and MOCUP rover from Telespazio

- Possible future developments: Event service, artificial communication delay and disruptions in DTN link, complex scenario with control authority hand-over

OOS Free-FlyerRover

The future of robots in space…


robotic exploration satellite servicing EVA support

Use Cases and Mission Scenario Analysis


- Use case analysis for space-robotic mission - What tasks have to be bedone?

- Layout of detailed scenarios as a composition of use cases for OOS, rover exploration and EVA support (free-flyer around ISS) in order to identify required service functionality

uc Ov erv iew of General Use Cases

Spacecraft

FDIR

Commissioning of Components

Superv ised Autonomy Operations

Manual Operations

Mission Monitoring

Mission Operations

Autonomous Operations

Mission Data Logging

Operation of Heterogeneous

Components

Shared Autonomy Operations

Agent

Mission Briefing

«invokes»

«invokes»

«include»

«include»

«invokes»

«include»

«include»

«include»

«include»

«include»

«extend»

Architecture of Remote Robot System


Iterative Development and Demonstration


DLR

DLR

DLR

ESTEC

servicelayer.robotKUKA LWR

RobotSimulator

servicelayer.mcmonitoring

action

RobotViewer

CommandUI

servicelayer.robot(server)

rmc-thalia

KUKA LWRRobot

SimulatorUDP servicelayer.mc

(client)

monitoring

action

Telespazio Vega

RobotViewer

CommandUI

servicelayer.robotKUKA LWRRobot

monitoring

action

Telespazio Vega

servicelayer.mc

RobotViewer

CommandUI

servicelayer.robot

KUKA LWRRobot

Simulator& cmd GUI

servicelayer.mcmonitoring

ESTEC

servicelayer.robotKUKA LWRRobot servicelayer.mc

monitoring

action

RobotViewer

CommandUI

monitoring & actionPort 4556

bidirectionalOn both sides

Demonstration at ESTEC


- Demonstration of selected interface services: Action and Monitoring

- Possible future developments: Event service, artificial communication delay and disruptions in DTN link, complex scenario with control authority hand-over

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